If you think SOPA sounds like Mexican soup and PIPA is the fetching sister of a certain princess, you can be excused for wondering why Wikipedia, Reddit and thousands of other websites are blacking out in protest Wednesday.

SOPA and PIPA are designed to crack down on websites based offshore that peddle illegal content — think pirated Hollywood blockbusters and fake Viagra. No one disputes that that’s a worthy goal. The rub is whether it would give the government and copyright holders too much control over the Web.

Here’s how it would work: If the Justice Department or a copyright holder believed a site was directing users to pirated content, they would go to court. Depending on who’s complaining, different remedies would come into play: In some instances a judge could order an Internet service provider like Verizon to cut off access to a site. In others, a search engine like Google could be directed to delete links to an infringing site. The idea is to starve the offending sites of the web traffic that keeps them in business.

Why’s it such a big deal?

What’s happening now on the Web, the bills’ backers say, is nothing short of rampant unpoliced theft of American goods. According to the U.S. Chamber of Commerce, so-called “rogue” sites draw hundreds of millions of clicks a year — at a huge toll to the American economy. The business lobby cites research by brand protection firm MarkMonitor estimating that illegal sites cost legitimate businesses more than $130 billion in revenue annually.

Enter SOPA and PIPA.

Will the government be able to censor the web if the bills pass?

That’s the crux of the debate. Google and First Amendment scholars like Harvard’s Laurence Tribe argue that SOPA would squelch free speech by giving private parties power to effectively cripple sites that allegedly — but not conclusively — steal copyrighted content. The simple filing of a complaint, they say, would exert huge pressure on the Internet ecosystem to blacklist an accused site. They also say it would give the feds dangerous new powers to go after sites for political reasons.

Nonsense, supporters say. The bills, they say, are narrowly crafted to target overseas sites that are “dedicated to theft of U.S. property.” Web companies are resorting to hyperbole and hysteria to maintain the status quo, backers argue.

Who wants the bills to pass?

The biggest backers of the antipiracy bills are the industries hardest hit by online piracy: the makers of music and movies. The Internet, and the explosion of illegal copying and sharing of music and movie files that came with it, has been economically devastating for Hollywood and recording studios, and they’ve been pushing lawmakers for years to hold Internet platforms more accountable for the illegal content that flows through their servers. The bills are also backed by makers of pharmaceuticals and luxury goods that want to strangle the market for knockoff goods. All told, hundreds of businesses led by the chamber are pushing hard for the bills.

Who’s against them?

Tech heavyweights including Google, eBay, and Wikipedia have been sounding alarms for over a year. They’ve been joined by an array of tech bloggers and Internet activists. And public interest groups such as Public Knowledge and the Electronic Frontier Foundation have been vocally spreading the tech community’s anti-SOPA message.

What’s this blackout about?

Think of it as a virtual strike. The Internet industry says the bills would “end the Web as we know it” —restricting how websites operate and what people share via social media. So some sites have banded together to show what would happen to the Web if the bills become law: big holes where household names like Wikipedia used to be.

Some companies are expressing their opposition in less dramatic ways. Google is placing a link on its home page to explain to users why it disagrees with the legislation. Scribd, a social publishing site, is showing visitors a pop-up box with its own notification. But not all Internet icons are taking part in the digital protest: Amazon, Yahoo, Facebook and eBay have remained relatively quiet.

What are the politics in Congress?

This is one of those rare times when members of both parties agree on something. Two-thirds of House Judiciary Committee members are ready to vote for SOPA, based on what they said and how they voted on amendments at a hearing last month. And 40 senators — 23 Democrats, 16 Republicans and one Independent — are on board with PIPA.

But don’t count on a presidential bill signing ceremony any time soon. The protest against the bills has its supporters reeling. Last week they jettisoned parts of the bill that would allow the domain names of sites offering illegal content to be blocked. And with the bloggers such as conservative Erick Ericson threatening to “do everything in my power” to defeat backers, undecided members may be wary of embracing the legislation in an election year.

What’s Obama think?

The White House waded into the debate over the weekend with a statement made it clear he wouldn’t sign either bill, without saying so. It’s a tough issue for the president, forcing him to choose between two of his most loyal constituencies (and biggest contributors of campaign cash): Hollywood and Silicon Valley.

That Hobson’s choice makes it unlikely that Obama would sign legislation this year. But next year, assuming he’s reelected, could be a different story. Extending an olive branch to Hollywood, the president went out of his way to say that online piracy is a “real problem” and legislation is needed to combat it.

How is SOPA different from PIPA?

Not by much. The bills have the same goals. When they were first introduced, there were some key differences in how the bills defined “rogue websites” and how rights holders could seek legal action. But revisions by SOPA author Rep. Lamar Smith (R-Texas) have narrowed the gap between the two bills so that they are now quite similar, except for some technical distinctions.

What’s gonna happen?

The next big test is on Jan. 24, when the Senate will vote whether to stop a filibuster on PIPA. One encouraging sign for supporters: Senate Majority Leader Harry Reid (D-Nev.) talked up the legislation in an interview on NBC’s “Meet the Press” over the weekend. But given that Congress has a hard time agreeing on postal office renamings — let alone legislation that has the Web community in a state of apoplexy — the odds of anything resembling SOPA or PIPA becoming law this year look exceedingly slim.

CORRECTION: An earlier version of this story misspelled the name of Laurence Tribe.